Power supply adapter



FIG. 1 is a perspective view of a power supply adapter showing a new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a right side elevational view thereof; and,

FIG. 5 is a top plan view thereof.

The back view is a mirror image of the front view, and the bottom plan view is a mirror image of the top plan view. 

CLAIM The ornamental design for a power supply adapter, as shown and described. 